PURPOSE: To examine acute alterations in white matter (WM)
diffusion based on diffusion tensor imaging (DTI) in youth with mild traumatic
brain injury (mTBI) relative to orthopedic injury (OI) controls.
METHODS: A prospective cohort study of 23 patients with mTBI and 20
OI controls ages 11-16 years were recruited from the emergency department (ED).
DTI was performed within 96 hours. Voxel based analysis quantified group
differences for DTI indices: fractional anisotropy (FA), mean diffusivity
(MD), axial diffusivity (AD), and radial diffusivity (RD). The Post
Concussion Symptom Scale assessed symptom burden.
RESULTS: Youth with mTBI had significantly higher symptom burdens
in the ED and at scanning than controls. The mTBI group had significantly
higher levels of FA and AD in several WM regions including the middle
temporal gyrus WM, superior temporal gyrus WM, anterior corona radiata,
and superior longitudinal fasciculus. The mTBI group had significantly lower
levels of MD and/or RD in a few WM regions including the middle frontal
gyrus WM and anterior corona radiata. Diffusion alterations correlated poorly
with acute symptom burden.
CONCLUSIONS: Alterations of diffusivity were detected in spatially
heterogeneous WM regions shortly after mTBI in youth. The pattern of
alterations may reflect restrictive water diffusion in WM early post-injury.
